AND

JOURNAL OF THE COAL AND IRON TRADES.

Vol. CVII.

FRIDAY MARCH 13, 1914.

No, 2776.

The Hygienic Aspect of the Coalmining Industry.

(Continued from page 512).

MINERS’ NYSTAGMUS: CAUSES,

Dr. F. Shufflebotham, M.A., M.D., J.P., of New-
castle, Staffordshire, delivered his fourth Milroy lecture
before the Royal College of Physicians, in London, on
Tuesday, March 3, this lecture being specially devoted
to miners’ nystagmus.

Dr. Shufflebotham said that miners’ nystagmus must
be regarded as the commonest of all occupational
diseases. In his opinion, the number of cases far
exceeded the numbers given in compensation statistics,
as those were cases in which undoubted incapacity for
work had been produced, and they did not take into
account the much larger numbers of early cases where
the patients were able to continue in their employment.
Dr. Court had stated as a result of examination of
several thousands of workmen that 35 per cent, of
coal-getters are subject to this disease to some extent.

Various authorities and statistics were quoted, and
the lecturer said that symptoms of nystagmus were
most commonly found among miners engaged in holing.
All observers agreed that the workmen who worked
the hardest and who earned the best wages were more
likely to be affected than those whose weekly output of
coal was smaller in amount. The disease was also found
among loaders, datallers, packers, as well as among the
firemen and colliery managers, and in these occupations,
like that of the holer, eye strain may be produced
through lowness of the roof of the roadways and the
workings in the mine.

Miners’ nystagmus seldom occurred before the age of
25, and not usually before a miner had worked for 10 years
underground. It would seem that the longer a man had
worked in the pit, the more likely was he to develop
nystagmus. This might be regarded as a general rule
which might be applied to all workers up to the time
when they have worked 30 years in the pit, after which
they did not appear to be so susceptible. The youngest
case that had come under Llewellyn’s notice was a boy
aged 15, and 47 of his cases developed the disease before
the age of 25. In McMurray’s series of 120 cases, nine
of the patients were 25 years and under. The shortest
time in which the 1 isease had been known to develop
after underground * ork was five months.

Symptom of Miners’ Nystagmus.

In considering the symptoms of miners’ nystagmus’
they must realise at the outset that they were dealing
not with a disease localised to the eyes, but with a
general disease, one symptom of which was oscillation
of the eyeballs. The teim “miners’ nystagmus” was
an unfortunate one, as it simply related to one symptom
of this complaint, and the nomenclature of this disease
had certainly given rise to a great deal of confusion,
even among medical men who practised in colliery
districts, and who were constantly coming in contact
with patients suffering from it. Nystagmus was a
symptom which was common to a large number of
diseases. The symptoms of this disease, however, were
not confined to oscillation of the eyeballs and any effects
which might Jesuit from this phenomenon. Theie might
be, and generally were, symptoms such as headache,
nausea, attacks of giddiness, muscular tremors, twitching
of the muscles in different parts of the body, especially
the muscles of the eyelids and the face and neck;
neurasthenia might be a prominent symptom, with its
associated conditions, such as a quickened pulse,
exaggerated reflexes, increased vasomotor irritability,
sleeplessness and nervous depression. All these
symptoms might be present in any given case of miners’
nystagmus, but in many cases only some of the
symptoms were present, and at given times the promi-
nent symptom—the oscillation of the eyeballs—might
actually be absent, although the patient was undoubtedly
suffering from the disease which they knew as miners’
nystagmus.

The lecturer examined some of these symptoms in
detail. He said that in cases of moderate severity
headache was perhaps the most frequent symptom. The

SYMPTOMS, AND TREATMENT.

character of the headache might vary in different
patients, according to whether there was any refractive
error or not; in the former case it was common to find
the headache of a frontal nature. The headaches might
be aggravated either by physical or mental exertion.
Attacks of giddiness were frequently found, and, as a
result of this, injuries could be easily understood to
occur, as he had seen one case of burns which resulted
from the patient falling over the fire. This symptom,
therefore, was one of great importance, as one that
totally incapacitated from work. Vomiting and nausea
were commonly found as subjective symptoms, most
usually after exertion, and especially in those cases
with a marked degree of astigmatism. Some patients
complained that the nausea was worse on getting up m
the morning, and, in those who had come under his
observation, Dr. Shufflebotham was convinced that this
was due to the nystagmus and not to other causes. It
must be recognised as an important symptom of miners’
nystagmus. The commonest complaint associated with
miners’ nystagmus was the jumping about or flickering
of the lights in the pit or the gas lights on the surface.
Those who knew what a St. Catharine’s wheel was,
generally compared the sensation to the lights moving
round like those wheels. Photophobia was a common
symptom, and a large majority of the cases complained
that they could not see at night, and others that the
symptoms were worse at twilight. The symptom of
night blindness was one of the earliest to be perceived
by the sufferer. Night blindness was undoubtedly
one of the most characteristic symptoms of miners’
nystagmus, and it was regarded by Court and Llewellyn
as being present in about 75 per cent, of all cases, and
the lecturer’s experience coincided. Among the rarer
subjective symptoms were double vision and photopsia.
Patients suffering from miners’ nystagmus very often
complained of nervousness, sleepnessness, and of mental
depression, and in some cases these feelings of nervous-
ness appeared before any of the other symptoms of the
disease. Mental symptoms of a more serious nature
than neurasthenia occurred in some few cases, and the
nervous depression was so great occasionally that the
patients have suicidal tendencies.

The lecturer said that the most important physical
sign associated with coalminers’ nystagmus was oscilla-
tion of the eyeballs. He examined this phenomenon in
detail. Clonic spasm of the eyelids was a common
symptom associated with miners’ nystagmus,, and in
some cases it was the most prominent objective
symptom. True clonic spasm was not what was
commonly known as blinking. It was essentially of the
nature of a fine and quick tremor. In addition to
oscillation of the eyeballs and clonic spasm, they
might often find tremors of the facial muscles,
of the eyebrows, and there might be in addition
a tremor of the whole head. In severe cases muscular
twifehings had been observed mother parts of the body,
but this might be evidence of neurasthenia rather than
of the disease. Ptosis, or dropping of the upper eyelids,
was often observed, especially when the patient had
tilted his head backwards for the purpose of steadying
it, but there was no loss of muscular power in the
eyelid. The gait of a typical case of miners’ nystagmus
was characteristic. The patient endeavouied to com-
pensate for his vis: a idefect by throwing the head back-
wards and keeping tl ^eyes down and walking stiffly
and if he were seen walking in the street he would be
observed to have his cap pulled right over his eyes. In
a large number of cases an accurate diagnosis could be
made by observing the characteristic way in which the
patient walked into a rcom. In severe cases the gait
might be ataxic. The examination of a case of miners’
nystagmus could never be regarded as complete unless
special attention was paid to the condition of the vision
apart from the oscillation of the eyeballs. As many
observers were of the opinion that some optic defect was
one of the principal factors in the production of miners’
nystagmus, it was important to ascertain in every case
whether the sight was normal or defective. A large
percentage of cases showed errors of refraction, this
percentage differing according to the observer. In other
cases it was possible to find evidence of old injury to the
eye, such as corneal opacities, while less frequently early
cataracts, glaucoma, or symptoms pointing to old iritis
were discoverable.

Mr. McMurray, of Stoke-on-Trent, had allowed the
lecturer to look through his notes of 120 cases, from

which it appeared that over two-thirds had some
refractive error. Harrison Butler, Llewellyn and
Normal also found a large percentage of cases in which
refractive error was present, but, on the other hand,
Snell and Dransart had admitted but little association of
refractive error with miners’ nystagmus. Astigmatism
of various kinds, he added, was the commonest form of
refractive error found. Dr. Shufflebotham further said
that of 64 cases where the observations had been com-
plete, McMurray found that in hypertropic astigmatism
there were 24 cases with the rule and 28 against, whilst
in myopic cases 12 were against the rule, without a
single one with it. As far as he knew, this observation
had not been previously recorded.

The lecturer quoted Mr. McMurray, of Stoke, Harrison
Butler, Dr. Folkor, Llewellyn, Cridland, Prof. George
Murray, &c. Cridland, he said, pointed out that there
was a great similarity between the fields of cases suffering
from miners’ nystagmus and those found in traumatic
neurasthenia, and threw out the suggestion that the
alteration in the field of vision in nystagmus cases was
of the same nature as that found in traumatic neuras-
thenia. The lecturer thought they might infer that the
symptom of nystagmus itself might be regarded as a
local symptom of neurasthenia.

Dr. Shufflebotham added that he had noticed in many
cases that when the patient was sitting down and had
put his head between bis legs for a short time, on raising
his head the eyes not only had the oscillations and clonic
spasm, the former being more marked, but there had
been a prominent bulging of the eyes, accompanied by
marked injection. He had found this symptom some-
times of the greatest value in doubtful cases, and had
never seen any reference to it by any other observer.
He then discussed the question of diagnosis, and, in the
course of considerable detail, incidentally remarked that
in cases in which no oscillation [of the eyeball was seen,
greater care was necessary to come to a reliable con-
clusion. He detailed a number of cases, and exhibited
some patients who were present.

Causation.

Dr. Shufflebotham then turned to the subject of the
causation of miners’ nystagmus, and said the four most
important factors which they had to consider were:
(1) defective illumination in the mine caused by the
low candle-power of the safety lamp ; (2) the peculiar
cramped position in which miners work, especially the
holers and other workers employed at the coal face
(3) the refractive errors found among the miners them-
selves ; and (4) the frequent injuries which miners
sustain during theii’ employment, and more especially
injuries to the eye itself; but it could not be said in any
case that miners’ nystagmus could be caused by any
one of these conditions alone, and the real truth probably
lay in the fact that the onset of the disease was due to
a combination of circumstances. They might say, how-
ever, that, except at the pit bottom, they always had
defective illumination in the coalmines of this country;
further, in perhaps the majority of cases they had a
cramped position at work ; ref ractive errors were at least
as common among miners as among other sections of
the community, and there was no doubt but that miners
were, by the nature of their employment, specially liable
to small in4 uries to the eye, such as abi-asions of the
cornea. On the surface, a worker could see when danger
was coming, and protect his eyes by means of his eyelids;
but in the defectively lighted pit this was impossible.
The general feeling at the present time, however, was
that the principal factor in the disease was the first one
that he had mentioned, the deficient illumination of the
mine; and at the Ophthalmological Congress which was
held at Oxford in 1912, when a discussion took place
upon the causes of miners’ nystagmus, it was the
unanimous opinion of the members of the congress that
the principal cause of miners’ nystagmus was the poor
lighting of the pit. In the last ten years he had only
seen three cases of miners’ nystagmus occurring among
ironstone workers who had always been employed in
naked light pits, and who had never worked in coalseams.

Dr. Shufflebotham went into the question of the present
methods of illumination in pits, and said that to those
who were interested in the technicalities of measuring
the illuminating power of safety lamps under varying
conditions in mines, he would refer them to the paper
of Dr. T. L. Llewellyn upon this subject. The second
factor in the production of this disease, the cramped
position of the miner while at work, was one to which
the late Simeon Snell paid special importance; but there
was no class of worker in the mine who appeared to be
immune from nystagmus, whether he worked in a
constrained position or not,

While a great many authors had neglected the subject
of errors of refraction in connection with miners’
nystagmus, there was a growing opinion that they played